Lighting appliance



y 21, 1935- L. c. DOANE LIGHTING APPLIANCE Filed Dec. 24, 1934 5Sheets-Sheet 1 J 9. M 3 y 0 f 0 4 2 M L 5 l 3 1 i... 2 2 m 7 llllll 1 2l 3, MN 2 8 8 M a 5 a a a 5 a a m H T W L ATTORNEY May 21, 1935.

L. C. DQANE LIGHTING APPLIANCE Filed D90. 24, 1934 3 Sheets-Sheet 2ATTORNEY May 21, 1935. L. c. DOANE LIGHTING APPLIANCE Filed Dec.

24, 1934 3 Sheets-Sheet I5 ATTORNEY Patented May 21, 1935 PATENT OFFlCELIGHTING APPLIANCE Leroy C. Donne, Meriden, Conn., assignor to Earl L.Canfleld, Hillside, N. J.

Application December 24, 1934, Serial No. 758,896

20 Claims.

The present invention relates to lighting appliances and is moreparticularly directed to lighting appliances designed to produceillumination solely by reflection of light.

The lighting appliances contemplated by the present invention areparticularly intended for use in providing a variable light source forgeneral or special purposes. For instance where it is used to testvisual acuity or the like, which depends upon the light intensity, itscolor, the direction of the light and the distribution of the light raysin the'area being illuminated it is important to maintain all thesefactors invariable, excepting intensity, and to vary the intensitythroughout a wide range, such as for example, from two to two hundred ormore foot candles.

According to the present invention the light beam is produced by meansof a reflector of substantially parabolic profile with the light sourceat the focus. A screen adjacent the light source cuts oil? direct lightso that it does not become admixed with the reflected light. Theintensity of the beam of reflected light is varied by some form of lightcontrolling device interposed between the light source and reflector tointercept light falling on the reflector. This intercepting device is sodesigned that the distribution of the light onto the profile of thereflector remains un altered so that the distribution of the lightreflected is not altered. In order to produce a beam free of striations,the reflector is preferably an aluminum reflector, specially treated todifiuse the rays.

When it is desired to effect a change in the color value of the emittedlight, provision is made for the insertion of one or more color screensin the path of the light rays. Inasmuch as these screens are notdepended upon for varying the light intensity, it is possible to obtaina variable intensity at constant color.

Other and further objects of the invention will appear as thedescription proceeds.

The accompanying drawings show, for purposes of illustrating the presentinvention, two of 'the many possible embodiments in which the inventionmay take form, it being understood that the drawings are illustrative ofthe invention rather than limiting the same. In these drawings:

Fig. 1 is a vertical sectional view through one form of lightingappliance employing movable shutter slats for varying the lightintensity;

Fig. 2 is an inverted plan view of the structure shown in Figure 1 withparts broken away and parts in section, the shutter slats being shown inthe open position;

Fig. 3 is a view similar to Figure 2 showing the shutter slats in closedposition;

Fig. 4 is an enlarged fragmentary view showing a detail of construction;

Fig. 5 is a side elevational view with parts in tsection showing amodified form of construcion;

Fig. 6 is a sectional view on the line 6-6 of Figure 5 looking in thedirection of the arrows; and

Fig. 7 is an inverted plan view of the construction shown in Figure 5.

In Figure 1 a supporting arm or bracket is indicated at l0 and a swivelll. These parts are secured to a socket cover and a reflector supportingstamping l2 having a lower flange l3 provided with elongated slots withenlarged ends M. The lamp socket is indicated at l5 and the lamp bulb atI6.

A reflector 20 preferably made of aluminum and of suitable profile(approximately parabolic) is detachably supported from the socket coverl2. A suitable form of attachment is indicated in the drawings and itcomprises nuts 2| and thumb screws 22. The heads of the thumb screws areadapted to pass through large ends of the slots It so that the reflectorcan be bodily removed from the socket holder for relamping. The innerflange 23 of the reflector supports a ring 24. The openings in this ringand in the flange 23 are large enough to accommodate the lamp bulb. Theform of support employed may include spacers 25 and screws 25'.

The ring 24 supports a lower plate 26 by means of spacers 21. Aplurality of shutter slats 28 are pivotedly secured between the ring 24and the plate 26 in the form of construction shown. These slats havepivot extensions 30 which extend down into holes 3| in the plate 26 andsimilar extensions 32 which extend up through holes 33 in spring members34. These spring members may be made of thin material and soldered orotherwise secured to the ring 24. Each spring member 34 forms aresilient mounting for two adjacent shutter slats. The springs act-tourge the shutter slats down toward the plate 26 and to prevent rattling.An oscillatory plate is mounted on a centrally disposed stud 36 carriedon the plate 26. The oscillatory plate 35 has a number of slots 31 toreceive extensions 38 carried by the slats 28. An operating arm 39 issecured to the plate 35 and extends out through a slot 40 in the mouthof the reflector.

To change the position of the shutter slats from fully open position ofFigure 2 to the fully closed position of Figure 3, it is merelynecessary to swing the arm 39 from one position to the other. Tofacilitate making this adjustment, flxed knobs 4l4l.are carried by thereflector so that one can grasp the movable handle and one or the otherof these knobs as desired. It will be noted that when the shutter slatsare in the open position they present practically no obstruction to thepassage of light out to the reflector. When they are closed they shutoff the light going to the reflector. At all times, however, openingsare of uniform width extending from top to bottom of the shutter so thatthe light distribution in axial planes is not altered. Inasmuch as thewedge of direct light passedout between any two adjacent slats reachesthe entire profile of the reflector the same as it would if there wereno slats, it is obvious that the light distribution is not altered.

' The slats are preferably made of chromium .plated steel. The lightreflected from the plates falls on the reflector and lights up the areasin direct shadow so that the entire surface of the reflectoris lighted.These rays are received at 'angles such that the reflections are wellout of the field oi the dominant parallel rays so that they do not alterthe light pattern of the principal beam. I

In the form shown in Figure l, the screening of the direct light. isaccomplished by the plate 26 which supports the shutter slats, but itcan,

of course, be accomplished in any other. suitable way, for example, by acup attached directly to the lamp bulb. Where the lower shuttersupporting part is in the form of a plate such as shown at 26, it isusually provided with ventilation holes indicated at 42, and the plateis isprovided with ventilationholes 43 offset 'sufli ciently to preventpassage of light. I

To provide for control of the color of the emitted beam, if desired, acolor filter plate 45 of colored glass may be employed. This plate issupported by two fixed clips, one of which is indicated'at 46 and amovableclip 41. The color filter glass is supported in a centerpiece 48having ventilation holes 49 and handle 50.

In the form shown'in Figure 5 a suitable support is indicated. It is inthe form of a swivel 5| supporting a cover member 52 and lamp'socket 53.The cover member 52 has 9. depending flange provided with a number ofsupporting screws 54. These screws detachably support the reflector andlight controlling elements. A tubular housing and reflector support isindicated at 55. It is outwardly flanged at 55 and a reflector 51similar to the reflector' 20 is secured to this flange by boltsindicated at 50.

A cup shaped stamping 59 is welded or otherwise secured at its upperedge 60 to the lower part of the tubular member 55. This stamping hasvertical slots indicated at 5| The bottom of the.

stamping is preferably provided with ventilation holes indicated at 62.A-pendent pivot member 53 is secured to the center of the bottom of thecup shaped member 59 and this in turn supports another cup shapedstamping 64, a slightly larger diameterv than the stamping 59. Thestamping 64 has ve'rtical slots 65 and bottom openings 66 forventilation. The larger cup shaped member 64 is angularly adjustableabout the axis of the lighting appliance so that the opening 65 may bemoved opposite the opening 6|,or adjusted to more or less close theseopenings and thereby control the amount of light which passes from thelight source 66 to the reflector 51. The

angularadjustment of the movable cup shaped member may be accomplishedby means of a threaded rod 61 passing through a threaded post 68 carriedby the lower stamping. The rod 61 has a thumb piece 69 outside of thereflector.

To provide for color control, color matching and the-like, the structureshown in Figures 5 to 7 is provided with two cylinders 10 and H, eachpreferably made of transparent glass of the desired color. The smallercylinder 10 is-supported in clips 12 secured on the upper face of a ring13. This ring is supported on the ends of i4 and 15 of the bent rod 16.The rod passes up through holes in guides I1 secured to the bottom ofthe fixed stamping 59. To adjust the height of the cylinder 10, it ismerely necessary to raise or lower the bent rod 16. When no colorcontrol is desired cylinder ill is in the upper position and housedwithin the tubular member 55. The outer cylinder ii is similarlysupported in clips I8 carried on'a ring 19 secured to the upper ends ofthe U-shapedrod 8 I. This rod extends through holes in the guides l1 andis adjusted upv and down as above described. Friction springs 82 arecarried in slots in the guide members 11 and bear on the rods to holdthe cylinders in the adjusted position.

From .the foregoing it is apparent that one is able to obtain from thestructures such as con templated herein a wide variation in theintensity of the beam of light produced by the reflector, and that thisvariation in intensity is accomplished without altering the lightpattern of the emtted beam, and without change in the color of the beamunless such change is desired. This 35 may be. obtained by adjusting thecolored glass partsinto or out of position. 1

It is obvious that the invention may be embodied in many forms andconstructions within the scope of the claims, and I wish it to beunderstood that the particular forms shown are but two of the manyforms. Various modifications and changes being possible, I do nototherwise limit myself in any way with respect thereto.

What is claimed is: v

1. In a lighting appliance, the combination with a fixed light source ofconstant intensity and an outwardly flaring reflector for producing abeam of reflected light of fixed pattern from said source,

and a screen for preventing admixture 'of direct 50 light, of a lightintercepting means between the light source and reflector for varyingthe intensity of the light in said beam without chang'-' ing the lightpattern from the reflector.

2. In a lighting appliance, the combination with a fixed light source ofconstant intensity and an outwardly flaring reflector for producing abeam of reflected light of fixed pattern from said source, and a screenfor preventing admixture of direct light, of a light intercepting meansbetween the 60 light source and reflector for varying the inand anadjustable light intercepting device to vary the amount of light whichfalls on the reflector without afiecting the distribution in axialplanes of the light transmitted through the device, whereby the spreadof the corresponding reflected beam is unaltered.

5. In combination, a light source, an open mouthed reflector having aprofile for reflecting light into a beam of predetermined spread, ascreen for preventing admixture of direct light, and an adjustable lightintercepting device to vary the amount of light which falls on thereflector without affecting the distribution in axial planes of thelight transmitted through the device,"whereby the spread of thecorresponding refleeting beam is unaltered, said device includingmovable members regularly disposed about the surface of a cylinder tointercept wedges of light of different angular extent.

6. In combination, a light source, an open mouthed reflector having aprofile for reflecting source and reflector, the shutterhaving axiallyextending openings to permit the light transmitted therethrough to fallon the entire profile of the reflector whereby thespread of thereflected beam is unaltered.

'7. In combination, a light source, an open mouthed reflector having aprofile for reflecting light into a. beam of predetermined spread, aring above the light source, a plurality of axially extending slatspivotally secured to the ring, supporting means for pivotally supportingthe lower end of the slats, means to swing the slats from a positionwhere they are radial and intercept substantially no light to a positionwhere they closed and intercept substantially all the light, and ascreen for preventing the emission of direct light into said reflectedbeam.

8. The combination set forth in claim '7, characterized in that the slatshifting plate is spaced below the screen and in that the plate andscreen have ventilation holes out of alignment.

9. The combination set forth in claim '7, wherein the pivotal supportsfor the slats include springs exerting axial pressure to keep the slatsfrom rattling.

10. In combination, a light source, an open mouthed reflector having aprofile for reflecting light into a beam of predetermined spread, a ringabove the light source, a plurality of axially extending slats pivotallysecured to the ring, supporting means for pivotally supporting the lowerends of the slats, an oscillatory plate pivoted from the slat supportand connected with the slats to swing the slats from a position wherethey are radial and intercept substantially no light to a position wherethey closed and intercept substantially all the light, and a screen forpreventing the emission of direct light into said reflected beam.

11. In combination, a light source, an open mouthed reflector having aprofile for reflecting light into a beam of predetermined spread, a ringabove the light source, a plurality of axially extending slats pivotallysecured to the ring, supporting means for pivotally supporting the lowerends of the slats, at oscillatory plate pivoted from the slat supportand connected with the slats to swing the slats from a position wherethey are radial and intercept substantially no light to a position wherethey closed and intercept substantially all the light, an operatinghandle carried by the plate and extending out through the reflector, anda screen for preventing the emission of direct light into said reflectedbeam.

12. A light controlling shutter, comprising a plate, a ring spaced fromthe plate and flxedly secured parallel to the plate, a plurality ofshutter slats pivotally supported between the plate and ring andannularly disposed so as to receive a light source, and an oscillatoryplate having connections with the shutter slats to swing the slats inunison.

'13. A light controlling shutter, comprising a circular plate, acircular ring spaced from the plate and fixedly secured parallel to theplate, a plurality of shutter slats pivotally supported between theplate and ring and annularly disposed so as to receive a light source,and an oscillatory plate pivotally secured to the plate and havingconnections withtheshutter slats to swing the slats in unison.

14. A light controlling shutter, comprising a plate, a ring spaced fromthe plate and fixedly secured parallel to the plate, a plurality ofshutter slats pivotally supported between the plate and ring andannularly disposed so as to receive a light source, and an oscillatoryplate having connections with the shutter slats to swing the slats inunison, the two plates being parallel and having ventilation holestherein, the holes being oifset to prevent escape of direct light.

15. A light controlling shutter, comprising a circular plate, a circularring spaced from the plate and fixedly secured parallel to the plate, aplurality of shutter slats pivotally supported between the plate andring and annularly disposed so as to receive a light source, and anoscillatory plate pivotally secured to and extending beyond the firstplate, the periphery of the oscillatory plate being provided with slotsto receive extensions on the slats and shift the slats in unison.

16. A light controlling device, comprising an open mouthed reflector ofcircular cross section, an axially disposed light source, a co-axialring secured inside the reflector near the small diameter portionthereof, a plate secured to the ring near the mouth of the reflector, aplurality of shutter slats pivotally secured to both the ring and theplate, and means for operating the slats in unison. a

17. In combination, a light source, an ope mouthed reflector having aprofile for reflecting light into a beam of predetermined spread, ascreen for preventing admixture of direct light with the beam ofreflected light, a variable opening shutter between the light source andreflector, the shutter having axially extending openlugs to permit thelight transmitted therethrough to fall on the entire profile of thereflector whereby the spread of the reflected beam is unaltered, and atranslucent color controlling screen removably carried across the mouthof the reflector.

18. In combination, a light source, an open mounted reflector having aprofile for reflecting light into a beam of predetermined spread, ascreen for preventing admixture of direct light with the beam ofreflected light, and a variable opening shutter between the light sourceand reflector, said shutter comprising a fixed cylinder about the lightsource and a concentric cylinder angularly adjustable thereto, thecylinder walls having longitudinally extending slots adapted to bebrought into registry to control the proportion of light flux emittedwhich falls on the reflector. I

19. In combination, a light source, an open mouthed reflector having aprofile for reflecting light into a beam of predetermined spread, a

' screen for'preventing the admixture of direct light with the beam 01'reflected light, a variable opening shutter between the light source andscreen for preventing the admixture of direct light with the beam orreflected light, a variable opening shutter between the light source andreflector, the shutter having axially extending openings to permit thelight transmitted therethrough to fall on the entire proflle of thereflector whereby the spread of the reflected beam is unaltered, and anadjustable color controlling cylinder movable from aposition where itintercepts the light falling on the reflector to a position out of thepath or the light rays which fall on the reflector.

LEROY (LDQANE.

